Fungicidal mixtures based on amide compounds

ABSTRACT

Fungicidal mixtures, comprising 
     A) an amide compound of the formula I                    
     in which 
     R 1 , R 2  are identical or different and are halogen, nitro, cyano, C 1 -C 8 -alkyl, C 2 -C 8 -alkenyl, C 2 -C 8 -alkynyl, C 1 -C 8 -haloalkyl, C 2 -C 8 -haloalkenyl, C 2 -C 8 -haloalkynyl, C 1 -C 8 -alkoxy, C 1 -C 8 -haloalkoxy, C 1 -C 8 -haloalkylthio, C 1 -C 8 -alkylsulfinyl or C 1 -C 8 -alkylsulfonyl; 
     x is 1, 2, 3 or 4; 
     y is 1, 2, 3, 4 or 5; 
     and 
     B) the amino compound of the formula II                    
     in a synergistically effective amount, methods for controlling harmful fungi using mixtures of the compounds I and II and the use of the compounds I and II for preparing such mixtures are described.

The present invention relates to fungicidal mixtures, comprising

A) an amide compound of the formula I

in which

R¹, R² are identical or different and are halogen, nitro, cyano,C₁-C₈-alkyl, C₂-C₈-alkenyl, C₂-C₈-alkynyl, C₁-C₈-haloalkyl,C₂-C₈-haloalkenyl, C₂-C₈-haloalkynyl, C₁-C₈-alkoxy, C₁-C₈-haloalkoxy,C₁-C₈-haloalkylthio, C₁-C₈-alkylsulfinyl or C₁-C₈-alkylsulfonyl;

x is 1, 2, 3 or 4;

y is 1, 2, 3, 4 or 5;

and

B) the amino compound of the formula II

in a synergistically effective amount.

Moreover, the invention relates to methods for controlling harmful fungiusing mixtures of the compounds I and II and to the use of the compoundsI and II for preparing such mixtures.

The compounds of the formula I, their preparation and their actionagainst harmful fungi have been disclosed in the literature (EP-A 545099).

Also known is the compound II (common name: spiroxamin), its preparationand its action against pests (EP-A 281 842).

It is an object of the present invention to provide mixtures which havean improved activity against harmful fungi combined with a reduced totalamount of active compounds applied (synergistic mixtures), with a viewto reducing the application rates and improving the activity spectrum ofthe known compounds I and II.

We have found that this object is achieved by the mixtures defined atthe outset. Moreover, we have found that applying the compounds I andthe compounds II simultaneously, that is either together or separately,or applying the compounds I and the compounds II in succession providesbetter control of harmful fungi than is possible with the individualcompounds alone.

The mixtures according to the invention act synergistically and aretherefore particularly suitable for controlling harmful fungi and inparticular powdery mildew fungi in cereals, vegetables, fruits,ornamental plants and grapevines.

The formula I represents in particular compounds in which R¹ is locatedin the 2-position and R² is located in the 4-position (formula I.1):

Particular preference is given to compounds of the formula I.1 in whichthe combination of the substituents corresponds to one row of Table Ibelow:

No. R¹ R² I-1 F F I-2 F Cl I-3 F Br I-4 Cl F I-5 Cl Cl I-6 Cl Br I-7 CF₃F I-8 CF₃ Cl I-9 CF₃ Br I-10 CF₂H F I-11 CF₂H Cl I-12 CF₂H Br I-13 CH₃ FI-14 CH₃ Cl I-15 CH₃ Br I-16 OCH₃ F I-17 OCH₃ Cl I-18 OCH₃ Br I-19 SCH₃F I-20 SCH₃ Cl I-21 SCH₃ Br I-22 S(O)CH₃ F I-23 S(O)CH₃ Cl I-24 S(O)CH₃Br I-25 SO₂CH₃ F I-26 SO₂CH₃ Cl I-27 SO₂CH₃ Br

Particular preference is given to the compounds I.1 in which R¹ is CF₃or halogen and R² is halogen.

When preparing the mixtures, it is preferred to employ the pure activecompounds I and II, to which further active compounds against harmfulfungi or other pests, such as insects, arachnids or nematodes, or elseherbicidal or growth-regulating active compounds or fertilizers can beadmixed.

The mixtures of the compounds I and II, or the compounds I and II usedsimultaneously, jointly or separately, exhibit outstanding activityagainst a wide range of phytopathogenic fungi, in particular from theclasses of the Ascomycetes, Basidiomycetes, Phycomycetes andDeuteromycetes. Some of them act systemically and can therefore beemployed as foliar- and soil-acting fungicides.

They are especially important for controlling a large number of fungi ina variety of crop plants, such as cotton, vegetable species (e.g.cucumbers, beans, tomatoes, potatoes and cucurbits), barley, grass,oats, bananas, coffee, maize, fruit species, rice, rye, soya, grapevine,wheat, ornamentals, sugar cane, and a variety of seeds.

They are particularly suitable for controlling the followingphytopathogenic fungi: Blumeria graminis (powdery mildew) in cereals,Erysiphe cichoracearum and Sphaerotheca fuliginea in cucurbits,Podosphaera leucotricha in apples, Uncinula necator in grapevines,Puccinia species in cereals, Rhizoctonia species in cotton, rice andlawns, Ustilago species in cereals and sugar cane, Venturia inaequalis(scab) in apples, Helminthosporium species in cereals, Septoria nodorumin wheat, Botrytis cinera (gray mold) in strawberries, vegetables,ornamentals and grapevines, Cercospora arachidicola in groundnuts,Pseudocercosporella herpotrichoides in wheat and barley, Pyriculariaoryzae in rice, Phytophthora infestans in potatoes and tomatoes,Plasmopara viticola in grapevines, Pseudoperonospora species in hops andcucumbers, Alternaria species in vegetables and fruit, Mycosphaerellaspecies in bananas and Fusarium and Verticillium species.

They can furthermore be employed in the protection of materials (forexample the protection of wood), for example against Paecilomycesvariotii.

The compounds I and II can be applied simultaneously, that is eithertogether or separately, or successively, the sequence, in the case ofseparate application, generally not having any effect on the result ofthe control measures.

The compounds I and II are usually applied in a weight ratio of from20:1 to 1:20, in particular from 10:1 to 1:10 and preferably from 5:1 to1:5.

Depending on the kind of effect desired, the application rates of themixtures according to the invention are, in particular in agriculturalcrop areas, from 0.01 to 8 kg/ha, preferably 0.1 to 5 kg/ha, inparticular 0.5 to 3.0 kg/ha.

The application rates of the compounds I are from 0.01 to 2.5 kg/ha,preferably 0.05 to 2.5 kg/ha, in particular 0.05 to 1.0 kg/ha.

Correspondingly, in the case of the compound II, the application ratesare from 0.01 to 10 kg/ha, preferably 0.05 to 5 kg/ha, in particular 0.1to 2.0 kg/ha.

For seed treatment, the application rates of the mixture are generallyfrom 0.001 to 250 g/kg of seed, preferably 0.01 to 100 g/kg, inparticular 0.01 to 50 g/kg.

If phytopathogenic harmful fungi are to be controlled, the separate orjoint application of the compounds I and II or of the mixtures of thecompounds I and II is effected by spraying or dusting the seeds, theplants or the soils before or after sowing of the plants, or before orafter plant emergence.

The fungicidal synergistic mixtures according to the invention or thecompounds I and II can be formulated for example in the form ofready-to-spray solutions, powders and suspensions or in the form ofhighly concentrated aqueous, oily or other suspensions, dispersions,emulsions, oil dispersions, pastes, dusts, materials for broadcasting orgranules, and applied by spraying, atomizing, dusting, broadcasting orwatering. The use form depends on the intended purpose; in any case, itshould ensure as fine and uniform as possible a distribution of themixture according to the invention.

The formulations are prepared in a manner known per se, e.g. by addingsolvents and/or carriers. The formulations are usually admixed withinert additives, such as emulsifiers and dispersants.

Suitable surfactants are the alkali metal salts, alkaline earth metalsalts and ammonium salts of aromatic sulfonic acids, e.g. ligno-,phenol-, naphthalene- and dibutylnaphthalenesulfonic acid, and of fattyacids, alkyl- and alkylarylsulfonates, alkyl, lauryl ether and fattyalcohol sulfates, and salts of sulfated hexa-, hepta- and octadecanols,or of fatty alcohol glycol ethers, condensates of sulfonated naphthaleneand its derivatives with formaldehyde, condensates of naphthalene or ofthe naphthalenesulfonic acids with phenol and formaldehyde,polyoxyethylene octylphenol ether, ethoxylated isooctyl, octyl- ornonylphenol, alkylphenol or tributylphenyl polyglycol ethers, alkylarylpolyether alcohols, isotridecyl alcohol, fatty alcohol/ethylene oxidecondensates, ethoxylated castor oil, polyoxyethylene alkyl ethers orpolyoxypropylene alkyl ethers, lauryl alcohol polyglycol ether acetate,sorbitol esters, lignosulfite waste liquors or methylcellulose.

Powders, materials for broadcasting and dusts can be prepared by mixingor jointly grinding the compounds I or II or the mixture of thecompounds I and II with a solid carrier.

Granules (e.g. coated granules, impregnated granules or homogeneousgranules) are usually prepared by binding the active compound, or activecompounds, to a solid carrier.

Fillers or solid carriers are, for example, mineral earths, such assilicas, silica gels, silicates, talc, kaolin, limestone, lime, chalk,bole, loess, clay, dolomite, diatomaceous earth, calcium sulfate,magnesium sulfate, magnesium oxide, ground synthetic materials andfertilizers, such as ammonium sulfate, ammonium phosphate, ammoniumnitrate, ureas, and products of vegetable origin, such as cereal meal,tree bark meal, wood meal and nutshell meal, cellulose powders or othersolid carriers.

The formulations generally comprise from 0.1 to 95% by weight,preferably 0.5 to 90% by weight, of one of the compounds I or II or ofthe mixture of the compounds I and II. The active compounds are employedin a purity of from 90% to 100%, preferably 95% to 100% (according toNMR spectrum or HPLC).

The compounds I or II, the mixtures, or the corresponding formulations,are applied by treating the harmful fungi, their habitat, or the plants,seeds, soils, areas, materials or spaces to be kept free from them witha fungicidally effective amount of the mixture, or of the compounds Iand II in the case of separate application.

Application can be effected before or after infection by the harmfulfungi.

USE EXAMPLES

The synergistic activity of the mixtures according to the invention canbe demonstrated by the following experiments:

The active compounds, separately or together, were formulated as a 10%strength emulsion in a mixture of 70% by weight of cyclohexanone, 20% byweight of Nekanil® LN (Lutensol® AP6, wetting agent having emulsifyingand dispersing action based on ethoxylated alkylphenols) and 10% byweight of Emulphor® EL (Emulan® EL, emulsifier based on ethoxylatedfatty alcohols) and correspondingly diluted with water to the desiredconcentration.

Evaluation was carried out by determining the infected leaf areas inpercent. These percentages were converted into efficacies. The efficacy(W) was calculated as follows using Abbot's formula:

W=(1−α)·100/β

α corresponds to the fungal infection of the treated plants in % and

β corresponds to the fungal infection of the untreated (control) plantsin %

An efficacy of 0 means that the infection level of the treated plantscorresponds to that of the untreated control plants; an efficacy of 100means that the treated plants were not infected.

The expected efficacies of the mixtures of the active compounds weredetermined using Colby's formula [R. S. Colby, Weeds 15, 20-22 (1967)]and compared with the observed efficacies.

Colby's formula: E=x+y−x·y/100

E expected efficacy, expressed in % of the untreated control, when usingthe mixture of the active compounds A and B at the concentrations a andb

x efficacy, expressed in % of the untreated control, when using activecompound A at a concentration of a

y efficacy, expressed in % of the untreated control, when using activecompound B at a concentration of b.

The results for the activity against mildew of wheat are shown in thetables below

Use Example 1 Activity Against Mildew of Wheat

Leaves of potted wheat seedlings of the culivar “Kanzler” were sprayedto run off point with an aqueous preparation of active compound whichhad been prepared from a stock solution made of 10% of active compound,85% of cyclohexanone and 5% of emulsifier and, 24 hours after the spraycoating had dried on, dusted with spores of mildew of wheat (Blumeriagraminis forma specialis tritici). The test plants were then placed in agreenhouse at 20-24° C. and 60-90% relative atmospheric humidity. After7 days, the extent of the mildew development was determined visually in% infection of the total leaf area. The percentages were converted intoefficacies.

TABLE A Individual active compounds Concentration of active compoundEfficacy in % of in the spray the untreated Example Active compoundliquor [ppm] control 1 Control (100% infection) 0 (untreated) 2 I-4 50 012.5 0 3 I-5 50 30 12.5 0 4 spiroxamine (II) 3 20 1.5 0

TABLE B Combinations according to the invention Mixture of activecompounds concentration mixing Observed Calculated Example ratioefficacy efficacy*) 5 I-4 + II 40 20 12.5 + 3 ppm 4:1 6 I-4 + II 80 2050 + 3 ppm 16:1 7 I-4 + II 40 0 50 + 1.5 ppm 32:1 8 I-5 + II 80 2012.5 + 3 ppm 4:1 9 I-5 + II 100 44 50 + 3 ppm 16:1 10 I-5 + II 100 3050 + 1.5 ppm 32:1 *)calculated using Colby's formula

Use Example 2 Curative Activity Against Puccinia Recondita on Wheat(Wheat Leaf Rust)

Leaves of potted wheat seedlings of the cultivar “Kanzler” were dustedwith spores of leaf rust (Puccinia recondita). Thereafter, the pots werekept for 24 hours in a chamber of high atmospheric humidity (90 to 95%)and at 20-22° C. During this time, the spores germinated and thegerminal tubes penetrated into the leaf tissue. The next day, theinfected plants were sprayed to run off point with an aqueousformulation of the active compound prepared from a stock solution madeof 10% of active compound, 85% of cyclohexanone and 5% of emulsifier.After the spray coating had dried on, the test plants were cultivated ina greenhouse at 20-22° C. and 65-70% relative atmospheric humidity for 7days. Thereafter, the extent of the rust fungus development on theleaves was determined. The percentages were converted into efficacies.

TABLE C Individual active compounds Concentration of active compoundEfficacy in % of in the spray the untreated Example Active compoundliquor [ppm] control 11 Kontrolle (100% infection) 0 (untreated) 12 I-4200 0 50 0 12.5 0 13 I-5 50 20 14 spiroxamine (II) 12.5 30 3 0 1.5 0

TABLE D Combinations according to the invention Mixture of activecompounds concentration mixing Observed Calculated Example ratioefficacy efficacy*) 15 I-4 + II 90 30 50 + 12.5 ppm 4:1 16 I-4 + II 30 012.5 + 3 ppm 4:1 17 I-4 + II 70 30 200 + 12.5 ppm 32:1 18 I-4 + II 40 050 + 3 ppm 16:1 19 I-4 + II 60 30 12.5 + 12.5 ppm 1:1 20 I-4 + II 70 050 + 1.5 ppm 32:1 21 I-5 + II 80 44 50 + 12.5 ppm 4:1 22 I-5 + II 60 2050 + 3 ppm 16:1 23 I-5 + II 40 20 50 + 1.5 ppm 32:1 *)calculated usingColby's formula

The test results show that the observed efficacy in all mixing ratios ishigher than the efficacy which had been calculated beforehand and usingColby's formula.

We claim:
 1. A fungicidal mixture, comprising A) an amide compound ofthe formula I

in which R¹, R² are identical or different and are halogen, nitro,cyano, C₁-C₈-alkyl, C₂-C₈-alkenyl, C₂-C₈-alkynyl, C₁-C₈-haloalkyl,C₂-C₈-haloalkenyl, C₂-C₈-haloalkynyl, C₁-C₈-alkoxy, C₁-C₈-haloalkoxy,C₁-C₈-haloalkylthio, C₁-C₈-alkylsulfinyl or C₁-C₈-alkylsulfonyl; x is 1,2, 3 or 4; y is 1, 2, 3, 4 or 5; and B) the amino compound of theformula II

in a synergistically effective amount.
 2. A fungicidal mixture asclaimed in claim 1, wherein the weight ratio of compound I to compoundII is from 20:1 to 1:20.
 3. A method for controlling harmful fungi,which comprises treating the harmful fungi, their habitat or the plants,seeds, soils, areas, materials or spaces to be kept free from them withan effective amount of the composition of claim
 1. 4. A method asclaimed in claim 3, wherein a compound I and the compound II are appliedsimultaneously either together or separately, or successively.
 5. Amethod as claimed in claim 3, wherein the compound I is applied in anamount of from 0.01 to 2.5 kg/ha.
 6. A method as claimed in claim 3,wherein the compound II is applied in an amount of from 0.01 to 10kg/ha.
 7. A composition as claimed in claim 1 which is conditioned intwo parts, one part comprising a compound of the formula I as set forthin claim 1 in a solid or liquid carrier and the other part comprisingthe compound of the formula II as set forth in claim 1 in a solid orliquid carrier.